| Value |
0.16
Unitless
|
| Organism |
Bacteria Escherichia coli |
| Reference |
Vogel U, Pedersen S, Jensen KF. An unusual correlation between ppGpp pool size and rate of ribosome synthesis during partial pyrimidine starvation of Escherichia coli. J Bacteriol. 1991 Feb173(3):1168-74 Table - link PubMed ID1704003
|
| Method |
Escherichia coli was exposed to partial pyrimidine starvation by feeding a pyrBI strain orotate as the only pyrimidine source. Bacteria were prelabeled with 32p of a low specific activity while growing on either uracil (20 ,ug/ml) or orotate (50 ,ug/ml). Then pulses of [3H]adenine were given, and the RNA was extracted at different intervals. The ratio of 3H to 32P was determined for both total RNA and rRNA (defined as RNA hybridizing to the rrnX operon on X DNA [ref 10 in article]). 1.5 min pulses |
| Comments |
The limiting value
of the composite ratio (3H/32P)rRNA/ 3H/32P)total RNA at
pulse times approaching time zero, is a measure of the
fraction of transcribing RNA polymerases engaged in formation
of rRNA chains, and as seen from Table link, this fraction
was lower in cells grown in orotate than in those grown in
uracil. See BNID 104808 |
| Entered by |
Uri M |
| ID |
104807 |